99 Percentile Qs Bank for JEE MainPhysicsElectromagnetic Induction
Two parallel rails of a railway track insulated from each other and with the ground are connected to a millivoltmeter. The distance between the rails is one metre. A train is travelling with a velocity of 72 ~km / h along the track. The reading of the millivoltmeter (in mV ) is (vertical component of the earth's magnetic induction is 2 10⁻⁵ ~T )
Options
- A1.44
- B0.72
- C0.4
- D0.2
Correct answer
C. 0.4
Step-by-step solution
Induced emf, e=B v l where, aligned v & = velocity of train & =72 5 18 & =20 ~m / s & =2 10⁻⁵ 20 1 & =2 10⁻⁵ 20 & =40 10⁻⁵ v & =40 10⁻² mV & =0.4 mV aligned